5.1 These test methods are useful in indicating the differences in flexure (breaking load, modulus of rupture) between various slates. These test methods also provide one element in the comparison of roofing slates under Specification C406 and structural slates under Specification C629.

1.1 These test methods cover determination of the breaking load of roofing slate and modulus of rupture of structural slate by use of simple three-point loading.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.